Plant-based wax compositions based on vegetable oils have become increasingly popular for use in the manufacture of candle wicks and candles, due in part to their relatively clean burning characteristics. Vegetable oils are often liquid at room temperature. In order to convert the vegetable oils to a wax-like consistency, they can be hydrogenated to various levels, and/or mixed with other ingredients such as fatty acids, monoglycerides, triglycerides and the like.
Complete hydrogenation of vegetable oils often leads to relatively high melting wax compositions which are brittle. The high melting points are beneficial because they allow the candle wicks and candles to remain stable during shipment and storage, even at relatively high temperatures experienced in southern climates. Yet the brittleness of the compositions can result in chipping and cracking of the compositions, before and during use of the candles.
Partial hydrogenation of vegetable oils yields wax compositions having greater flexibility and pliability, and less brittleness, which are desirable for use in candle wicks and candles. However, these wax compositions have lower melting points which may permit deformation or destabilization of the candles during shipment and storage at high temperature. Also, partially hydrogenated vegetable oils can oxidize during prolonged exposure to atmospheric air, especially at higher temperatures. Oxidation causes the wax compositions to be less uniform, and distorts their chemical make-up and burning characteristics.
There is a need or desire for vegetable oil-based wax compositions having a combination of controlled melting points, high flexibility and pliability, low brittleness, and chemical stability.